The present disclosure relates to a display device, and more particularly, to a display device with an integrated touch screen built in a panel.
Touch screens are a type of input device that is included in display devices such as Liquid Crystal Displays (LCDs), Field Emission Displays (FEDs), Plasma Display Panel (PDPs), Electroluminescent Displays (ELDs), and Electrophoretic Display (EPDs), and enables a user to input information by directly touching a screen with a finger, a pen or the like while looking at the screen of the display device.
Particularly, the demand of display devices with integrated in-cell type touch screen, which include a plurality of built-in elements configuring the touch screen for slimming portable terminals, such as smart phones and tablet Personal Computers (PCs), is recently increasing.
Display devices with an integrated touch screen are categorized into an optical type, a resistive type, a capacitive type, etc. according to a sensing type. Recently, the capacitive type is mainly used for increasing the sharpness of a screen and the accuracy of touch.
The technology of a display device with integrated capacitive-type touch screen has been disclosed in U.S. Pat. No. 7,859,521, etc. Particularly, U.S. Pat. No. 7,859,521 discloses the technology of a display device with integrated mutual capacitance type touch screen.
In a related art display device with an integrated touch screen disclosed in U.S. Pat. No. 7,859,521, a plurality of common electrodes for display are segmented into a plurality of touch driving areas and touch sensing areas, thereby allowing a mutual capacitance to be generated between the touch driving area and the touch sensing area. Therefore, the related art display device measures the change of a mutual capacitance that occurs in touch, and thus determines whether there is a touch.
In order for the related art display device with an integrated touch screen to simultaneously perform a display function and a touch function, a plurality of common electrodes are respectively connected to a display driver Integrated Circuit (IC) and a touch IC. Also, the touch IC needs to perform a switching function that applies a common voltage to the common electrodes when the panel is driven in a display mode and applies signals necessary for touch to the common electrodes when the panel is driven in a touch mode. Moreover, the intensity of a touch sensing signal needs to increase for enhancing touch sensitivity, for which the touch IC needs to apply a high voltage to a driving electrode.
Therefore, the related art display device with an integrated touch screen needs to separately include a Flexible Printed Circuit (FPC) for a touch IC and an FPC for a Display Driver IC (DDI) to connect the common electrodes and the display driver IC. Further, a touch IC for switching the common voltage is required to be separately manufactured.
Moreover, a separate circuit block needs to be added for applying a high voltage to a driving electrode, and when the touch IC includes the separate circuit block internally, the size of the touch IC is enlarged.